1. Field of the Invention
The present invention relates generally to devices for supporting wheelchairs and, more particularly, to devices for supporting wheelchairs when they are tilted backward.
2. Description of the Prior Art
Wheelchairs serve an important function and are used by many people. Aside from the many benefits that wheelchairs provide, there are a number of undesirable aspects of wheelchair use. For a person who spends a great deal of time in a wheelchair, the person may experience back fatigue and circulation problems. One remedy to the back problems and circulation problems is getting out of the wheelchair and lying down on a bed or sofa. However, getting out of the wheelchair may neither be desirable or possible for a number of reasons. In this respect, it would be desirable if a wheelchair device were provided which alleviated back fatigue and circulation problems without having the person get out of the wheelchair.
One solution to the problem of back fatigue and circulation problems associated with a wheelchair is to provide for tilting the wheelchair backwards as the person is seated in the wheelchair. Throughout the years, a number of innovations have been developed relating to the tilting of wheelchairs, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 3,255,040; 4,527,944; 4,725,188; 4,725,730; and 4,834,411.
More specifically, U.S. Pat. No. 3,256,040 discloses a reclining attachment for wheelchairs which includes an hand-operated tilt mechanism that is suitable for tilting the wheelchair for moving the wheelchair over curbs. Many persons may not have the physical strength to operate such a hand-operated tilt mechanism. In this respect, it would be desirable if a wheelchair device were provided which included an electrically operated tilt mechanism.
U.S. Pat. No. 4,527,944 discloses another wheelchair tilting device which is hand-operated. A complicated array of linkage bars convert a rotational hand-operated crank into a tilting of the wheelchair. The complex array of linkage bars is subject to significant wear and tear. In this respect, it would be desirable if a wheelchair device were provided which employed a tilting mechanism that does not require a complex array of linkage bars.
U.S. Pat. No. 4,725,188 discloses an article of furniture that receives a wheelchair and permits the wheelchair to be tilted backwards. The furniture includes track rail members that have upwardly opening concave tracks which extend rearwardly from a lowermost point to a first slightly raised position and then extend along curved paths in an are having about the same or slightly larger radius of curvature as the large wheels of the wheel chair to be accommodated. The tilting of the wheelchair can be powered by a battery-powered electric motor. In the tilted position, the person's head is resting upon headrest. A number of disadvantages are associated with this device. For one thing, the concave tracks and the curved arcs of the wheel rests assume a standard distance between opposing wheels of a wheelchair. In fact, such a distance is not standardized. This is particular so because wheelchairs are of different sizes to accommodate persons ranging from small children to large adults. In this respect, it would be desirable if a wheelchair tilting device were provided which is readily adaptable to a wide variety of sizes of wheelchairs. In addition, with the device disclosed in the patent, the headrest is located at a fixed distance from the back of a wheelchair. In this respect, it would be desirable if a wheelchair tilting device were provided which included an adjustable headrest.
U.S. Pat. No. 4,726,730 discloses an electrically powered wheelchair tilting device which does not include a headrest and which does include a jacking mechanism for raising and lowering the person in the tilted wheelchair. The presence of a jacking mechanism is an unnecessary complexity for a wheelchair tilting mechanism which is designed simply to relieve back aches and circulation problems. In this respect, it would be desirable if a wheelchair tilting device were provided which does not include a jacking mechanism for raising and lowering the tilted wheelchair.
U.S. Pat. No. 4,834,411 discloses a wheelchair tilting device that is hand operated. The wheelchair is first secured to the tilt frame with clamps, and the wheelchair is tilted so that the person seated in the wheelchair has one's head positioned over a sink for shampooing. This wheelchair tilting device does not have a headrest as this would get in the way of the shampooing process. Moreover, when the wheelchair is tilted back on its large rear wheel, the small front wheels of the wheelchair are left unsecured in the air. In this respect, it would be desirable if a wheelchair tilting device were provided which included a device for securing the front wheels when the wheelchair is tilted backwards.
Still other features would be desirable in a wheelchair tilting apparatus. For example, it would be deskable if the wheelchair tilting apparatus had its own arm rests. It would also be desirable if the arm rests could be tilted somewhat out of the way when the tilting process takes place. It would also be desirable if the wheelchair tilting apparatus had an adjustable back stop for positioning the back of the wheelchair in the apparatus. It would also be desirable if the wheelchair tilting apparatus had a device for fixing the small front wheels of the wheelchair in a predetermined position.
Thus, while the foregoing body of prior art indicates it to be well known to use wheelchair tilting devices, the prior art described above does not teach or suggest a wheelchair tilting apparatus which has the following combination of desirable features: (1) alleviates back fatigue and circulation problems without having the person get out of the wheelchair; (2) includes an electrically operated tilt mechanism; (3) does not require a complex array of linkage bars; (4) is readily adaptable to a wide variety of sizes of wheelchairs; (5) includes an adjustable headrest; (6) does not include a jacking mechanism for raising and lowering the tilted wheelchair; (7) includes a device for securing the front wheels when the wheelchair is tilted backwards; (8) has its own arm rests; (9) has arm rests which can be tilted somewhat out of the way when the firing process takes place; (10) has an adjustable back stop for positioning the back of the wheelchair in the apparatus; and (11) has a device for fixing the small front wheels of the wheelchair in a predetermined position. The foregoing desired characteristics are provided by the unique wheelchair tilting apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.